1. Field of the Invention
The present invention relates to video signal processors corresponding to a plurality of broadcasting systems and television receivers using the same. Particularly, the present invention relates to a video signal processor utilizing the characteristic of a data driven processor, and a television receiver using such a video signal processor.
2. Description of the Background Art
These several years have seen the spread of a television receiver that realizes video signal processing by converting a video signal into a digital signal and processing this digital signal. This digital signal process requires a processing performance of considerably high speed. Furthermore, signal processing of high complexity is required in accordance with the higher picture quality in clear-vision broadcasting and high-vision broadcasting.
The structure of the apparatus accommodating digital broadcasting will become more versatile as the services for practical application of digital broadcasting begins to be provided. More specifically, not only video signals, but also computer-oriented data and the like will be received through digital broadcasting. A television receiver incorporated with the function of a computer, a set-top box used in connection with an a receiver directed to analog broadcasting, an extended board incorporating only the processing function of a received video signal and the like are envisaged.
The digital television broadcasting in U.S.A. includes a plurality of image formats differing in the scanning system (interlace scanning, non interlace scanning), number of scanning lines, number of pixels, aspect ratio, and the like. The structure of a television receiver per se directed to the television broadcasting has also become versatile.
Research is in progress to accommodate the variety of broadcasting systems by incorporating a DSP (Digital Signal Processor) in a television receiver and altering the software of the DSP. FIG. 1 shows a schematic structure of a television receiver incorporating a DSP disclosed in Japanese Patent Laying-Open No. 4-120978. The television receiver includes an antenna 100, a tuner 101, an A/D (Analog/Digital) converter 102, a D/A (Digital/Analog) converter 105, a drive circuit 106, a deflection coil 107, a CRT (Cathode Ray Tube) 108, operation units 1-4 (134-137), control units 1-4 (138-141), a memory control unit 142, program storage units 1-4 (143-146), a reset circuit 147, a connector 148 and a program memory 149. One DSP is formed of an operation unit i (i=1-4) and a control unit i (i=1-4).
After being reset by reset circuit 147, memory control unit 142 reads out a program executed by each DSP from program memory 149 via connector 148 to load that program to program storage units 1-4 (143-146).
The broadcasting wave received by antenna 100 is channel-tuned by tuner 101, whereby a desired channel signal is received. Tuner 101 provides the video detection signal extracted from the channel signal to A/D converter 102. A/D converter 102 converts the video detection output from tuner 101 into a digital signal. The digital signal is provided to operation unit 1 (134). According to the program loaded in program storage unit 1 (143) under control of control unit 1 (138), operation unit 1 (134) sequentially applies an operation on the video detection output converted into a digital signal from A/D converter 102 for output.
Similarly, sequential operation is carried out in operation units 2-4 (135-137). The video data output from operation unit 4 (137) is applied to D/A converter 105. D/A converter 105 converts the video signal into an analog signal to provide the video to CRT 108 via drive circuit 106. Operation unit 4 (137) generates at the same time a synchronizing signal applied to deflection coil 107. This synchronizing signal is converted into an analog signal by D/A converter 105 to be applied to deflection coil 107 as a deflection pulse.
The invention disclosed in Japanese Patent Laying-Open No. 9-247573 relates to a television receiver that processes a video signal by a plurality of operation elements arranged in an array.
Since a great amount of operation is required in video signal processing, the video signal must be processed in parallel by a plurality of DSPs as in the invention disclosed in Japanese Patent Laying-Open No. 4-120978 or by a plurality of operation elements as in the invention disclosed in Japanese Patent Laying-Open No. 9-247573. By such a structure, a television receiver accommodating a variety of broadcasting systems can be realized with a common hardware.
However, the number of DSPs or the operation elements must be altered when the specification of the television receiver itself is to be changed, such as in the case of modifying the hardware structure to suit the load of video signal processing. Furthermore, it is necessary to significantly alter the design of the hardware structure to load a microprogram or the design of the microprogram per se in accordance with change in the number of DSPs or the operation elements. Therefore, there was a problem that the object of accommodating a variety of broadcasting systems with a common hardware could not be achieved.
An object of the present invention is to provide a video signal processor that can accommodate a variety of broadcasting systems by just a simple hardware modification.
Another object of the present invention is to provide a video signal processor that can automatically identify the broadcasting system to generate and output video corresponding to that broadcasting system.
A further object of the present invention is to provide a television receiver that can accommodate a variety of broadcasting systems by just a simple hardware modification.
Still another object of the present invention is to provide a television receiver that can automatically identify the broadcasting system to generate and output video corresponding to that broadcasting system.
According to an aspect of the present invention, a video signal processor includes a receiver unit receiving a broadcasted wave, an identify unit identifying the broadcasting system according to a signal received by the receiver unit, and a plurality of data driven processors processing a video signal received by the receiver unit according to the broadcasting system identified by the identify unit.
Since the plurality of data driven processors process a video signal received by the receiver unit according to the broadcasting system identified by the identify unit, video data corresponding to the identified broadcasting system can be generated.
According to another aspect of the present invention, a video signal processor includes a receiver unit receiving a broadcasted wave, a detachable external storage unit storing a microprogram processing a video signal corresponding to a broadcasting system, and a plurality of data driven processors reading out and executing the microprogram stored in the external storage unit.
Since the plurality of data driven processors can read out and execute the microprogram from a detachable external storage unit, the user can view video at the desired broadcasting system by selecting and loading an external storage unit.
According to a further aspect of the present invention, a television receiver includes a receiver unit receiving a broadcasted wave, an identify unit identifying a broadcasting system according to the signal received by the receiver unit, a plurality of data driven processors processing a video signal received by the receiver unit according to the broadcasting system identified by the identify unit, and a display unit providing a display of a video signal processed by the plurality of data driven processors.
Since the plurality of data driven processors process a video signal received by the receiver unit according to the broadcasting system identified by the identify unit, video data corresponding to a broadcasting system can be generated.
According to still another aspect of the present invention, a television receiver includes a receiver unit receiving a broadcasted wave, a detachable external storage unit storing a microprogram processing a video signal corresponding to a broadcasting system, a plurality of data driven processors reading out and executing the microprogram stored in the external storage unit, and a display unit providing a display of a video signal processed by the plurality of data driven processors.
Since the plurality of data driven processors read out and execute a microprogram from a detachable external storage unit, the user can view video in a desired broadcasting system by selecting and loading an external storage unit.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.